Never is. The report I read seemed to suggest parents were too stupid to have actually made a decision about this, and that by contacting all those who hadn't had it they would instantly and eagerly snap it up.
Perhaps some will, but I made a conscious and informed decision not to go ahead, and will not be panicking into changing my mind now.
I made a careful and informed decision to give singles, and informed my GP surgery - didn't stop the ruddy PCT sending me endless appointments for ds, though. I cancelled the first couple but then got fed up with it.
He's since had the pre-school MMR booster, because I felt by four I knew he didn't have any particular risk factors such as auto-immune disease.
I've had loads of letters too - the receptionist told me to just bin them when I phoned, they were that interested. But suddenly this week they phoned and wanted to know the dates - I know why now, reading this report.
Wish the BBC would stop talking about children who haven't had the MMR as unvaccinated - how can they possibly know?